Antennas in mobile communications apparatuses such as cell phones, wireless LAN, etc., which are used in as wide frequency bands as several hundreds of MHz to several GHz (for instance, 470-770 MHz in digital terrestrial broadcasting), are required to have high gain in such wide frequency bands, and small sizes with low height. As a small antenna suitable for such mobile communications apparatuses, JP 49-40046 A proposes an antenna which is made smaller by using a magnetic material having large dielectric constant ∈r and specific permeability μr to reduce wavelength to 1/(∈r·μr)1/2, and JP 9-507828 A describes that sintered hexagonal ferrite is suitable for antennas. Hexagonal ferrite is a magnetic material having an easy magnetization axis in a plane perpendicular to a c-axis, which may be called “ferrox planar type ferrite.”
JP 56-64502 A discloses a dipole-type antenna comprising a conductor pattern embedded in a Ni ferrite substrate. However, even a ferrite-made antenna cannot be sufficiently small and operable in a wide band, unless having a structure effectively providing inductance while suppressing a capacitance component.